"The pound will never be ditched in favour of the euro while Gordon Brown holds the reins of power, his aides insisted last night. Scotland on Sunday can reveal that although Treasury officials are already reviewing the infamous "five tests" devised by Brown to decide whether to join the single currency, the Chancellor has ruled it out. Brown will seize the opportunity to scupper one of Tony Blair’s remaining political ambitions by ruling that he will shun the euro as it would critically damage Britain’s economic competitiveness."